Over 90% of the teens with asthma and diabetes in our study met the criteria for adequate health literacy. Although there are no other studies of health literacy in this specific population, other studies using variations of the TOFHLA in other populations have found adequate literacy rates among English-speaking adults that have ranged from 60 to over 90%.21,40,41
We found a significant racial disparity in that black teens evidenced lower health literacy than White teens, and this difference was not explained by socioeconomic status. This finding was consistent with previous research in adults, which has found independent relationships between health literacy, race, and socioeconomic status.42,43
Given the relatively small minority population in our study, additional research will be needed to explore potential causes.
Patterns of variations in the rates of Internet use among teens with chronic illnesses were consistent with patterns found in a general population survey of adolescents. For example, the percentages of teens in our study who reported using the Internet and who reported using it daily were nearly identical to those found for teens in the 2005 Pew Internet and American Life Survey.5
Not surprisingly, the area where Internet use diverged was in the search for health-related information. We found that 48% of teens in our study searched for information about health, diet, and physical fitness compared to only 30% of teens in the national survey. We found that teens' use of the Internet to search for online health information did not differ by gender, race, zip code median income, or disease. Younger teens, however, were significantly less likely to seek such information than older teens. This finding is consistent with developmental research showing that teens do not begin to take independent responsibility for disease management until mid-adolescence (ages 15–17).44
Contrary to research in adults, our analysis did not find a significant relationship between search for online health information and health literacy. Youths with lower health literacy are seeking health information online at the same rate as those with higher literacy.
While health literacy was not associated with self-reported use of online health information, we found a highly significant relationship between health literacy and intent to use recommended sites in the near future. Significant bivariate relationships were also seen between intent to use online health information and perceived ease of use, and with perceived usefulness. In the multivariate model only health literacy and perceived usefulness remained significantly associated with intent to use. A qualitative analysis of the information from the telephone interviews conducted for this study supported the importance of perceived usefulness in the decision to try and to continue to use online health resources.45
Those who did not visit any Web sites in the follow-up period cited reasons, including lack of need, lack of time, and lack of interest while those who used Web sites and reported the intention to continue use described the Web sites they used with words including “helpful,” “useful,” and “informative.”
Interestingly, demographic and Internet use characteristics were not significant predictors of intent to use. The lack of race or income effects in our study is important because much discussion has revolved around sociodemographic barriers to Internet use, commonly referred to as the “digital divide,” and whether such barriers limit the value of Internet-based health tools in health disparity populations.46–48
We cannot generalize our findings to the larger population of teens with asthma and diabetes because the sample of teens in this study all had access to and chose to use healthcare services in a specialty care clinic; however, the absence of disparities associated with race or income in our sample suggests that Web-based patient tools may be acceptable to diverse teens receiving treatment in clinic settings, and hence these tools are unlikely to exacerbate existing health disparities in such patients.
Teens in our study may differ from the general population due to self-selection factors. Teens, or parents of teens, who had low perceived health literacy may have opted to decline participation to avoid potential discomfort or embarrassment associated with the literacy assessment process. Such self-selection may have biased our sample toward higher literacy youths. The exclusion of a small number of potential participants due to significant English or communication deficiencies also biased the literacy of our sample upward. Additional research is needed to understand the relationship between health literacy and use of online health resources in broader populations of teens with more varied health literacy levels. Such research should also include additional measures of health literacy. While the TOFHLA is one of the most widely used and validated measures of functional health literacy, it does not directly measure all elements of health literacy (e.g., ability to obtain information or ability to understand oral communication).
Assessment of perceived ease of use and perceived usefulness of resource sheet Web sites occurred after a verbal description of the Web sites rather direct exposure to the sites. This is consistent with much of the counseling or social marketing that patients receive about online health information. Direct exposure to Web sites or previous experience with the Web sites (which was not assessed) may, however, have generated higher or lower perceptions of ease of use and usefulness. Finally, our study design did not permit the validation of self-reported use of online health resources. Reported use may reflect a degree of social desirability bias yielding an over-reporting of actual use.
This study shows that many teens with asthma and diabetes are currently using the Internet as a resource for health information and support. After receiving a verbal description of selected Web sites and an information sheet, most teens in our study reported the intent to try recommended health resource Web sites, but their anticipated commitment to become regular users of such sites depended on their health literacy and their beliefs about the usefulness of the sites. Belief that a Web site was easy to use was not a significant predicator of intent to use after controlling for health literacy and perceived usefulness. These findings suggest that just making a Web site easy to use may not generate sustained use. Instead, teens with asthma and diabetes are most likely to intend to use online health resources when they believe that the Web site will improve their health or healthcare practices and when they have the underlying skills to be effective users.